<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		
		<script type="text/javascript">
		
			alert(b);
			
			/* var a ;
			
			alert( typeof(a) );
			
			a = "zhangsanfeng"
			
			alert(typeof a)
			
			a = true;
			alert(typeof a) */
		</script>
	</body>
</html>
